INTROPICA

9-19

Authors: Juan Aguirre-Pabón, Javier Rodríguez-Barrios, Rodulfo Ospina-Torres

The aim of this work was to evaluate the spatial variation of the macroinvertebrate biomass and density drift on two stations with different degree of disturbance (flow regulated and higher sediment amount in one of them) in the lower basin of Gaira River (Santa Marta, Colombia). We carried out three surveys per station using drift nets during 24-hour periods, collecting samples each four hours. We found differences on abundance-, biomass- and drift density between sites and samples, where the less disturbed station had the higher values. The daily variation of drift was highest at night. Leptohyphidae, Chironomidae, Hydropsychidae and Elmidae were the most abundant drifting taxa. The differences can be related to river flow variability and sediment transport, in spite of the marginal value of both magnitude and frequency of the disturbance.

31-36

Authors: Massiel Pinto, Gunta Smits Briedis

Aquatic hyphomycetes are a heterogeneous group of microorganisms that are characterized by their abilities to colonize, degrade and modify the plant material in the water, allowing its use by other organisms living in the aquatic ecosystem. Due to the importance of this hyphomycetes for the energy budget in low order lotic systems, this study was carried out in order to determine, in a preliminary way, the species richness of the aquatic hyphomycetes in four streams located in the northern slope of the Cordillera de la Costa (Venezuela), and also to assess if there is any similarity between the communities of hyphomycetes present in these streams. We collected samples of water foam (three per sampling site) and identified the species of hyphomycetes; then, we performed a cluster analysis to evaluate similarities between streams as a function of species richness. A total of 27 species were identified: 20 at Cuyagua stream, 10 at Cumboto stream, 18 at Cata stream, 17 at San Miguel creek (reservoir) and 2 at the estuarine environment of San Miguel creek. Based on species composition of the aquatic hyphomycetes, the Cata stream and San Miguel creek showed the highest similarity between sites, and both of them were similar to the Cuyagua stream; the Cumboto stream showed the lesser similarity when compared with the rest of the sampling sites.

47-57

Authors: Gilberto Orozco-Berdugo, Javier Rodríguez-Barrios, Rodulfo Ospina-Torres

The metabolic activity of sediments was measured over an altitudinal gradient in a mountain tropical river (Sierra Nevada de Santa Marta – Colombia). It was related along the river basin with climatic and hydrologic parameters during the dry season. Additionally, observations of the metabolic activity and the variation of the P/R ratio during a day were made. Measures were made with a light-dark bottle method and two hours exposition. For the estimation of the real area, images of previously weighted subsamples of sediment were processed with an ImageJ 1.40g computer program. Over the altitudinal gradient we find that community respiration (CR) was higher than the gross primary productivity (GPP), also P/R < 1. The light intensity was the most important variable and was related with the P/R ratio on the upper basin and with GPP over the entire gradient. Our results shows that the substrate sediment is strong heterotrophic over the entire basin but mainly on the middle part of the river.

69-79

Authors: Yadis Álvarez, Esteban Álvarez, Jonathan Cano, Diego Suescún

The leaf area (LA) is an main functional trait and it is related with the plant development. Understanding their variation is important for many studies in plant ecology. We chose 13 species that occur in Caribbean tropical dry forests in Colombia. From one tree of each species were collected at least 15 leaves to measure your area (LA), length (L) and width (W). We analized the relationship between LA and L and W dimensions and select the best statistic adjustment. These variables were transformed logaritmically. In this case, LA was the dependent variable and L and W are explanatory variables. We classified the data in seven categories based on leave characteristics (compound leaves, simple, with area greater or lesser than 50 cm2 and, with area greater or lesser than 100 cm2) to develop models that could be used to estimate the LA of other species not included in the sample. It showed a strongly lineal relationship between LA logarithms and the L*A product, for the species as well as these categories of species. The prediction error (EP %, from Spanish) from all models were, in general, inferior to ± 1%. Thus, these are adequated to estimate LA for each species or any categorie. In a particular way, the lineal model for all the species shows higher estimation of the LA to dry forest species analized. Generally, errors are lower or close to 10% which can be considered acceptable in statistics terms according to other allometric studies. Finally, this model: In (AF) = -1,80 + 0,967 ln (L*A) (r2= 99,5%, p < 0.001) is appropiate to calculate leaf area for dry tropical forest species without using destructive methods.

91-96

Authors: Vivian Villalba Vizcaíno

Giardia intestinalis is a parasite of worldwide distribution, causing acute non-bacterial diarrhea. Parasite transmission is fecal-oral and it can get between humans, humans-animals and animals-animals, being waterborne transmission main, so it is generally considered that this disease is an important health problem.. This protozoan parasite has a high genetic variability, because it has a diverse range of host. This protozoan has eight genotypes identified, with a host-specific relationship; but some of them could be non-specific, which allows zoonotic transmission. There are some techniques conventionally used for the diagnosis of infection with G. intestinalis, however these have low sensitivity due to intermittent elimination of cysts; but to investigate this area, many new techniques are available, such as Polymerase Chain Reaction(PCR), Restriction fragment lenght polymorphism (RFLP), Sequencing. It’s not clear the role of pets in zoonotic transmission, genotype distribution in our environment and impact in health population. The aim of this paper is showing particular characteristics of G. intestinalis, health problems that this parasite represent to population, the molecular tools available and its potentiality to resolve some questions about this important protozoan.

115-120

Authors: Carlos E. Brochero Bustamante, Sindy J. Colorado Martínez, Paula A. Sepúlveda-Cano

Chlosyne lacinia (Lepidoptera: Nymphalidae) also known as sunflower patch, is an important economic pest in this crop due to the defoliant behavior in larval stage. In addition to the sunflower, other known alternate hosts could be used for breeding in captivity. In order to describe the different development stages and their duration on its alternate hosts in Magdalena Tithonia diversifolia, we rear this species in the laboratory of entomology at the Universidad del Magdalena, with a diet based on leaves of this plant. The life cycle of C. lacinia lasted 38-42 days. The eggs took an average of six days to hatch. The larval stage had a mean duration of 20 days, and the pupal and adult, lasting 6 and 8 days respectively. The results of this work they differ from those made by others on the breeding of this species in laboratory on two main aspects: a significant reduction in the total cycle time and one more stage in the larval development of the insect

129-135

Authors: Guilherme Barattela, Marcus Polette

The standards by which beach management systems are efficiently managed are best achieved through the application of strict guidelines and requirements, such as those that will be necessary to achieve ISO/TC 228/WG 5 certification. Standards such as these will aid in providing quality services for beachgoers. It is possible verify that the requirements of a standard are met by inserting them into an evaluation matrix that is adapted from the Model for Performance Evaluation of Integrated Coastal Management. Thus, we can ascertain the efficiency of the current management system. This paper focused on the perception of 11 institutions that are involved directly in local tourism in one Brazilian beach, Praia Brava, for which the effectiveness of applied management systems was checked. This beach was used as a particular case study for proving the inadequate management of Brazilian coastal environments.